Janssen PKC et al. (2008) Serotonin transporter promoter region (5-HTTLPR) polymorphism is associated with the intravaginal ejaculation latency time in Dutch men with lifelong premature ejaculation. J Sex Med [doi: 10.1111/j.1743-6109.2008.01033.x]

New research has identified a gene involved in serotonin (5-hydroxytryptamine [5-HT]) control that can delay ejaculation, and determines whether a man is likely to experience premature ejaculation (PE). In response to earlier studies linking decreased 5-HT neurotransmission and/or 5-HT receptor dysfunction to PE, Janssen et al. investigated polymorphisms of the 5-HT transporter-linked promoter region (5-HTTLPR) gene. This gene has a short (S) allele and a long (L) allele; men with the LL genotype are likely to have decreased 5-HT neurotransmission, which might predispose them to PE.

Janssen et al. prospectively assessed 181 Dutch Caucasian men (89 with lifelong PE, mean age 36.0 years; 92 normal controls, mean age 53.6 years). All participants underwent genotyping by means of DNA isolation and PCR analysis. No significant difference was observed in the 5-HTTLPR polymorphisms between the two groups; however, among men with PE, those who possessed the LL genotype had a shorter mean time until ejaculation (13.2 s) than those with the SL or SS genotypes (25.3 s and 26.04 s, respectively). Time to ejaculation was determined over the course of 1 month by the female partners of men with PE; the women used a stopwatch to measure the time until ejaculation each time they had intercourse.

The authors suggest that other genetic factors also determine the time until ejaculation, and are continuing to investigate the role of 5-HT receptors and metabolic pathways in the regulation of ejaculation.